Green’s Dictionary of Slang

to make homosexual advances towards.

1744		Ordinary of Newgate Account 24 Dec. 14/2: James Ruggles [...] waited only till he saw them closely engaged, came up to them, and seizing upon the Gentleman, cry’d, D - n your Blood you Dog, what are you a Mollying one another?
1746		Proceedings Old Bailey 17 Jan. 58/2: I never mollied you. My Lord, I never laid my Hand upon him, nor touch’d him; I never touch’d the Man in my Life.